Date: Sat, 5 Dec 2015 20:53:13 +0800 From: Howard Su <howard0su@gmail.com> To: Andrew Turner <andrew@freebsd.org> Cc: "src-committers@freebsd.org" <src-committers@freebsd.org>, "svn-src-all@freebsd.org" <svn-src-all@freebsd.org>, "svn-src-head@freebsd.org" <svn-src-head@freebsd.org> Subject: Re: svn commit: r291852 - in head/sys: arm/arm arm/include cddl/dev/fbt/arm Message-ID: <CAAvnz_pQ99yX8FMTp3YpgVMKzkYahGANZZCjukeh3u%2B88Ld0ug@mail.gmail.com> In-Reply-To: <201512050932.tB59Waii003325@repo.freebsd.org> References: <201512050932.tB59Waii003325@repo.freebsd.org>
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On Saturday, December 5, 2015, Andrew Turner <andrew@freebsd.org> wrote: > Author: andrew > Date: Sat Dec 5 09:32:36 2015 > New Revision: 291852 > URL: https://svnweb.freebsd.org/changeset/base/291852 > > Log: > Move the check to see if we are tracing a function with the DTrace > Function > Boundary Trace to assembly to reduce the overhead of these checks. > > Submitted by: Howard Su <howard0su@gmail.com <javascript:;>> > Relnotes: Yes > Differential Revision: https://reviews.freebsd.org/D4266 > > Modified: > head/sys/arm/arm/exception.S > head/sys/arm/arm/genassym.c > head/sys/arm/arm/trap-v6.c > head/sys/arm/arm/undefined.c > head/sys/arm/include/trap.h > head/sys/cddl/dev/fbt/arm/fbt_isa.c > > Modified: head/sys/arm/arm/exception.S > > ============================================================================== > --- head/sys/arm/arm/exception.S Sat Dec 5 08:52:37 2015 > (r291851) > +++ head/sys/arm/arm/exception.S Sat Dec 5 09:32:36 2015 > (r291852) > @@ -52,13 +52,15 @@ > #include <machine/asm.h> > #include <machine/armreg.h> > #include <machine/asmacros.h> > +#include <machine/trap.h> > + > __FBSDID("$FreeBSD$"); > > #ifdef KDTRACE_HOOKS > .bss > .align 4 > - .global _C_LABEL(dtrace_invop_calltrap_addr) > -_C_LABEL(dtrace_invop_calltrap_addr): > + .global _C_LABEL(dtrace_invop_jump_addr) > +_C_LABEL(dtrace_invop_jump_addr): > .word 0 > .word 0 > #endif > @@ -361,9 +363,39 @@ END(data_abort_entry) > */ > ASENTRY_NP(undefined_entry) > PUSHFRAMEINSVC /* mode stack, build trapframe > there. */ > + mov r4, r0 /* R0 contains SPSR */ > adr lr, exception_exit /* Return from handler via > standard */ > - mov r0, sp /* exception exit routine. Pass > the */ > - b undefinedinstruction /* trapframe to the handler. */ > + mov r0, sp /* exception exit routine. pass > frame */ > + > + ldr r2, [sp, #(TF_PC)] /* load pc */ > +#if __ARM_ARCH >= 7 > + tst r4, #(PSR_T) /* test if PSR_T */ > + subne r2, r2, #(THUMB_INSN_SIZE) > + subeq r2, r2, #(INSN_SIZE) > +#else > + sub r2, r2, #(INSN_SIZE) /* fix pc */ > +#endif > + str r2, [sp, #TF_PC] /* store pc */ > + > +#ifdef KDTRACE_HOOKS > + /* Check if dtrace is enabled */ > + ldr r1, =_C_LABEL(dtrace_invop_jump_addr) > + ldr r3, [r1] > + cmp r3, #0 > + beq undefinedinstruction > + > + and r4, r4, #(PSR_MODE) /* Mask out unneeded bits */ > + cmp r4, #(PSR_USR32_MODE) /* Check if we came from usermode > */ > + beq undefinedinstruction > + > + ldr r4, [r2] /* load instrution */ > + ldr r1, =FBT_BREAKPOINT /* load fbt inv op */ > + cmp r1, r4 > + bne undefinedinstruction > + > + bx r3 /* call invop_jump_addr */ > +#endif > + b undefinedinstruction /* call stadnard handler */ > END(undefined_entry) > > /* > > Modified: head/sys/arm/arm/genassym.c > > ============================================================================== > --- head/sys/arm/arm/genassym.c Sat Dec 5 08:52:37 2015 (r291851) > +++ head/sys/arm/arm/genassym.c Sat Dec 5 09:32:36 2015 (r291852) > @@ -118,6 +118,7 @@ ASSYM(MD_TP, offsetof(struct mdthread, m > ASSYM(MD_RAS_START, offsetof(struct mdthread, md_ras_start)); > ASSYM(MD_RAS_END, offsetof(struct mdthread, md_ras_end)); > > +ASSYM(TF_SPSR, offsetof(struct trapframe, tf_spsr)); > ASSYM(TF_R0, offsetof(struct trapframe, tf_r0)); > ASSYM(TF_R1, offsetof(struct trapframe, tf_r1)); > ASSYM(TF_PC, offsetof(struct trapframe, tf_pc)); > > Modified: head/sys/arm/arm/trap-v6.c > > ============================================================================== > --- head/sys/arm/arm/trap-v6.c Sat Dec 5 08:52:37 2015 (r291851) > +++ head/sys/arm/arm/trap-v6.c Sat Dec 5 09:32:36 2015 (r291852) > @@ -66,6 +66,10 @@ __FBSDID("$FreeBSD$"); > #include <machine/db_machdep.h> > #endif > > +#ifdef KDTRACE_HOOKS > +#include <sys/dtrace_bsd.h> > +#endif > + > extern char fusubailout[]; > extern char cachebailout[]; > > @@ -561,6 +565,13 @@ abort_fatal(struct trapframe *tf, u_int > const char *rw_mode; > > usermode = TRAPF_USERMODE(tf); > +#ifdef KDTRACE_HOOKS > + if (!usermode) { > + if (dtrace_trap_func != NULL && (*dtrace_trap_func)(tf, > far)) > + return (0); > + } > +#endif > + > mode = usermode ? "user" : "kernel"; > rw_mode = fsr & FSR_WNR ? "write" : "read"; > disable_interrupts(PSR_I|PSR_F); > > Modified: head/sys/arm/arm/undefined.c > > ============================================================================== > --- head/sys/arm/arm/undefined.c Sat Dec 5 08:52:37 2015 > (r291851) > +++ head/sys/arm/arm/undefined.c Sat Dec 5 09:32:36 2015 > (r291852) > @@ -99,10 +99,6 @@ __FBSDID("$FreeBSD$"); > > #define COPROC_VFP 10 > > -#ifdef KDTRACE_HOOKS > -int (*dtrace_invop_jump_addr)(struct trapframe *); > -#endif > - > static int gdb_trapper(u_int, u_int, struct trapframe *, int); > > LIST_HEAD(, undefined_handler) undefined_handlers[MAX_COPROCS]; > @@ -206,12 +202,6 @@ undefinedinstruction(struct trapframe *f > > PCPU_INC(cnt.v_trap); > > -#if __ARM_ARCH >= 7 > - if ((frame->tf_spsr & PSR_T) != 0) > - frame->tf_pc -= THUMB_INSN_SIZE; > - else > -#endif > - frame->tf_pc -= INSN_SIZE; > fault_pc = frame->tf_pc; > > /* > @@ -350,12 +340,6 @@ undefinedinstruction(struct trapframe *f > #endif > return; > } > -#ifdef KDTRACE_HOOKS > - else if (dtrace_invop_jump_addr != 0) { > - dtrace_invop_jump_addr(frame); > - return; > - } > -#endif > else > panic("Undefined instruction in kernel.\n"); > } > > Modified: head/sys/arm/include/trap.h > > ============================================================================== > --- head/sys/arm/include/trap.h Sat Dec 5 08:52:37 2015 (r291851) > +++ head/sys/arm/include/trap.h Sat Dec 5 09:32:36 2015 (r291852) > @@ -7,4 +7,5 @@ > #define GDB5_BREAKPOINT 0xe7ffdefe > #define PTRACE_BREAKPOINT 0xe7fffff0 > #define KERNEL_BREAKPOINT 0xe7ffffff > +#define FBT_BREAKPOINT 0xe7f000f0 > #endif /* _MACHINE_TRAP_H_ */ > > Modified: head/sys/cddl/dev/fbt/arm/fbt_isa.c > > ============================================================================== > --- head/sys/cddl/dev/fbt/arm/fbt_isa.c Sat Dec 5 08:52:37 2015 > (r291851) > +++ head/sys/cddl/dev/fbt/arm/fbt_isa.c Sat Dec 5 09:32:36 2015 > (r291852) > @@ -35,11 +35,10 @@ > #include <sys/param.h> > > #include <sys/dtrace.h> > +#include <machine/trap.h> > > #include "fbt.h" > > -#define FBT_PATCHVAL 0xe7f000f0 /* Specified undefined > instruction */ > - > #define FBT_PUSHM 0xe92d0000 > #define FBT_POPM 0xe8bd0000 > #define FBT_JUMP 0xea000000 > @@ -53,15 +52,20 @@ fbt_invop(uintptr_t addr, uintptr_t *sta > struct trapframe *frame = (struct trapframe *)stack; > solaris_cpu_t *cpu = &solaris_cpu[curcpu]; > fbt_probe_t *fbt = fbt_probetab[FBT_ADDR2NDX(addr)]; > + register_t fifthparam; > > for (; fbt != NULL; fbt = fbt->fbtp_hashnext) { > if ((uintptr_t)fbt->fbtp_patchpoint == addr) { > cpu->cpu_dtrace_caller = addr; > > - /* TODO: Need 5th parameter from stack */ > + /* Get 5th parameter from stack */ > + DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT); > + fifthparam = *(register_t *)frame->tf_usr_sp; > + DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT | > CPU_DTRACE_BADADDR); > + > dtrace_probe(fbt->fbtp_id, frame->tf_r0, > frame->tf_r1, frame->tf_r2, > - frame->tf_r3, 0); > + frame->tf_r3, fifthparam); > > cpu->cpu_dtrace_caller = 0; > > @@ -77,7 +81,7 @@ fbt_patch_tracepoint(fbt_probe_t *fbt, f > { > > *fbt->fbtp_patchpoint = val; > - cpu_icache_sync_range((vm_offset_t)fbt->fbtp_patchpoint, 4); > + cpu_icache_sync_range((vm_offset_t)fbt->fbtp_patchpoint, > sizeof(val)); > } > > int > @@ -104,13 +108,6 @@ fbt_provide_module_function(linker_file_ > if (name[0] == '_' && name[1] == '_') > return (0); > > - /* > - * Architecture-specific exclusion list, largely to do with FBT > trap > - * processing, to prevent reentrance. > - */ > - if (strcmp(name, "undefinedinstruction") == 0) > - return (0); > - > instr = (uint32_t *)symval->value; > limit = (uint32_t *)(symval->value + symval->size); > > @@ -125,12 +122,12 @@ fbt_provide_module_function(linker_file_ > fbt = malloc(sizeof (fbt_probe_t), M_FBT, M_WAITOK | M_ZERO); > fbt->fbtp_name = name; > fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, > - name, FBT_ENTRY, 3, fbt); > + name, FBT_ENTRY, 2, fbt); > fbt->fbtp_patchpoint = instr; > fbt->fbtp_ctl = lf; > fbt->fbtp_loadcnt = lf->loadcnt; > fbt->fbtp_savedval = *instr; > - fbt->fbtp_patchval = FBT_PATCHVAL; > + fbt->fbtp_patchval = FBT_BREAKPOINT; > fbt->fbtp_rval = DTRACE_INVOP_PUSHM; > fbt->fbtp_symindx = symindx; > > @@ -157,7 +154,6 @@ again: > start = (uint32_t *)symval->value; > if (target >= limit || target < start) > break; > - instr++; /* skip delay slot */ > } > } > > @@ -171,7 +167,7 @@ again: > fbt->fbtp_name = name; > if (retfbt == NULL) { > fbt->fbtp_id = dtrace_probe_create(fbt_id, modname, > - name, FBT_RETURN, 3, fbt); > + name, FBT_RETURN, 2, fbt); > } else { > retfbt->fbtp_next = fbt; > fbt->fbtp_id = retfbt->fbtp_id; > @@ -187,7 +183,7 @@ again: > else > fbt->fbtp_rval = DTRACE_INVOP_POPM; > fbt->fbtp_savedval = *instr; > - fbt->fbtp_patchval = FBT_PATCHVAL; > + fbt->fbtp_patchval = FBT_BREAKPOINT; > fbt->fbtp_hashnext = fbt_probetab[FBT_ADDR2NDX(instr)]; > fbt_probetab[FBT_ADDR2NDX(instr)] = fbt; > > While I am here, 1. Remove a copy&paste code to skip "delay slot" which ARM doesn't have. 2. Support fifth arg in fbt. this leads to add missing KDTRACE hook code in trap-v6.c -- -Howard
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